Archive link for the Telegraph article posted upthread by @MrsOvertonsWindow, I think it's the same one
https://archive.ph/g7W4o
The BTP said....“Who British Transport Police transgender colleagues may search is determined by an interaction between the legal framework of the Police and Criminal Evidence Act (1984), Code of Practice on the Exercise by Constables of Powers of Stop and Search of the Person in Scotland 2017, and the Equality Act (2010), with the correct application of occupational requirement, and not limited to the provisions of the Gender Recognition Act (GRA) (2004).
See! Quite clear. Don't know what everyone's worrying about 
Although spare a thought for PC Britney, whose gagging to search his her first woman uterus-haver, but the Postman hasn't been yet to deliver his her GRC.